Mima Mounds | Walk Through a Natural Mystery

There are few things left unexplained on our planet, but the mima mounds near Olympia are one of them. With several paved and unpaved trails, you can actually take a stroll through this unsolved natural mystery.

The Mima Mounds Natural Area Preserve (map) is located about an hour and half south of Seattle. The address officially says Olympia, but the mima mounds are found just outside the town of Littlerock. There’s a small parking lot at the trailhead, but keep in mind a Discover Pass is required. NOTE: You’ll hear plenty of gun fire when you’re in the mima mounds parking lot. Don’t worry: it’s from the neighboring shooting range.

So, what in the world are the mima mounds? That’s a great question. No one can explain why they exist. In easy terms, each mound is about 3-to-8 feet tall and about 20-to-30 feet around. There are thousands of mounds stretched over the 637-acre preserve. The question of how the mima mounds were formed is still unanswered. There are several different theories, including: glacial melting during the ice age, earthquakes, wind-blown sediment, shrinking and swelling of clay, pocket gophers, and even extraterrestrials.

The best part: you can talk a walk through this unsolved mystery. There are several different trails through the Mima Mounds Natural Area Preserve. You can do this 2.75-mile roundtrip hike (suggested by the Washington Trails Association) or you can just stroll the different trails. It’s impossible to get lost because 1) it’s a prairie, so you can pretty much see the entire preserve from wherever you’re standing, and 2) every trail through the mima mounds is a loop trail. My dad and I walked the 2-mile south “long loop” (plus some) when we recently visited.

There’s no shortage of history at the Mima Mounds Natural Area Preserve. The mounds were once home to Native Americans, they received their name during an expedition in 1841, and they became a National Natural Landmark in 1966. That’s just scratching the surface. There’s an interpretive center on-site that explains the vast history of the mima mounds, and you also get a slightly elevated view from the deck there. Unfortunately, there’s no location on the preserve to get a really good above ground-level view of the mima mounds.

My dad and I visited in the fall, but we hear the best time to visit the mima mounds is in the spring. That’s when the mounds are covered with several different types of wildflowers. The mima mounds are also home to numerous butterflies (click here for a butterfly guide) and other wildlife. My dad and I saw a northern harrier flying through the preserve when we were there, and it sounds like that’s a pretty common sight.

A hike through the Mima Mounds Natural Area Preserve offers some exercise, but it also allows you speculate, investigate, and wonder why in the world the mima mounds exist. You can come up with your own theories (or backup others) as you weave in and out of this natural phenomenon. Will we ever know the real answer to why the mima mounds exist? Probably not, but I personally think it’s better that way. Everyone can draw their own conclusions.

Have you ever visited the Mima Mounds Natural Area Preserve? How was your experience? What do you think caused the mima mounds? We’d love to hear from you! Please leave a comment below or connect with us on Twitter, Facebook, and Google+. Don’t forget to also check out Seattle Bloggers for more great places to visit around the Emerald City!